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authorLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
committerLinus Torvalds <torvalds@ppc970.osdl.org>2005-04-16 15:20:36 -0700
commit1da177e4c3f41524e886b7f1b8a0c1fc7321cac2 (patch)
tree0bba044c4ce775e45a88a51686b5d9f90697ea9d /ipc/msgutil.c
downloadlinux-linaro-precise-1da177e4c3f41524e886b7f1b8a0c1fc7321cac2.tar.gz
Linux-2.6.12-rc2
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
Diffstat (limited to 'ipc/msgutil.c')
-rw-r--r--ipc/msgutil.c127
1 files changed, 127 insertions, 0 deletions
diff --git a/ipc/msgutil.c b/ipc/msgutil.c
new file mode 100644
index 00000000000..66cfb87646e
--- /dev/null
+++ b/ipc/msgutil.c
@@ -0,0 +1,127 @@
+/*
+ * linux/ipc/util.c
+ * Copyright (C) 1999, 2004 Manfred Spraul
+ *
+ * This file is released under GNU General Public Licence version 2 or
+ * (at your option) any later version.
+ *
+ * See the file COPYING for more details.
+ */
+
+#include <linux/spinlock.h>
+#include <linux/init.h>
+#include <linux/security.h>
+#include <linux/slab.h>
+#include <linux/ipc.h>
+#include <asm/uaccess.h>
+
+#include "util.h"
+
+struct msg_msgseg {
+ struct msg_msgseg* next;
+ /* the next part of the message follows immediately */
+};
+
+#define DATALEN_MSG (PAGE_SIZE-sizeof(struct msg_msg))
+#define DATALEN_SEG (PAGE_SIZE-sizeof(struct msg_msgseg))
+
+struct msg_msg *load_msg(const void __user *src, int len)
+{
+ struct msg_msg *msg;
+ struct msg_msgseg **pseg;
+ int err;
+ int alen;
+
+ alen = len;
+ if (alen > DATALEN_MSG)
+ alen = DATALEN_MSG;
+
+ msg = (struct msg_msg *)kmalloc(sizeof(*msg) + alen, GFP_KERNEL);
+ if (msg == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ msg->next = NULL;
+ msg->security = NULL;
+
+ if (copy_from_user(msg + 1, src, alen)) {
+ err = -EFAULT;
+ goto out_err;
+ }
+
+ len -= alen;
+ src = ((char __user *)src) + alen;
+ pseg = &msg->next;
+ while (len > 0) {
+ struct msg_msgseg *seg;
+ alen = len;
+ if (alen > DATALEN_SEG)
+ alen = DATALEN_SEG;
+ seg = (struct msg_msgseg *)kmalloc(sizeof(*seg) + alen,
+ GFP_KERNEL);
+ if (seg == NULL) {
+ err = -ENOMEM;
+ goto out_err;
+ }
+ *pseg = seg;
+ seg->next = NULL;
+ if (copy_from_user(seg + 1, src, alen)) {
+ err = -EFAULT;
+ goto out_err;
+ }
+ pseg = &seg->next;
+ len -= alen;
+ src = ((char __user *)src) + alen;
+ }
+
+ err = security_msg_msg_alloc(msg);
+ if (err)
+ goto out_err;
+
+ return msg;
+
+out_err:
+ free_msg(msg);
+ return ERR_PTR(err);
+}
+
+int store_msg(void __user *dest, struct msg_msg *msg, int len)
+{
+ int alen;
+ struct msg_msgseg *seg;
+
+ alen = len;
+ if (alen > DATALEN_MSG)
+ alen = DATALEN_MSG;
+ if (copy_to_user(dest, msg + 1, alen))
+ return -1;
+
+ len -= alen;
+ dest = ((char __user *)dest) + alen;
+ seg = msg->next;
+ while (len > 0) {
+ alen = len;
+ if (alen > DATALEN_SEG)
+ alen = DATALEN_SEG;
+ if (copy_to_user(dest, seg + 1, alen))
+ return -1;
+ len -= alen;
+ dest = ((char __user *)dest) + alen;
+ seg = seg->next;
+ }
+ return 0;
+}
+
+void free_msg(struct msg_msg *msg)
+{
+ struct msg_msgseg *seg;
+
+ security_msg_msg_free(msg);
+
+ seg = msg->next;
+ kfree(msg);
+ while (seg != NULL) {
+ struct msg_msgseg *tmp = seg->next;
+ kfree(seg);
+ seg = tmp;
+ }
+}